title: The protein folding challenge in psychrophiles: facts and current issues.
abstract: The protein folding process in psychrophiles is impaired by low temperature, which exerts several physicochemical constraints, such as a decrease in the folding rate, reduced molecular diffusion rates and increased solvent viscosity, which interfere with conformational sampling. Furthermore, folding assistance is required at various folding steps according to the protein size. Recent studies in the field have provided contrasting and sometimes contradictory results, although protein folding generally appears as a rate-limiting step for the growth of psychrophiles. It is proposed here that these discrepancies reflect the diverse adaptive strategies adopted by psychrophiles in order to allow efficient protein folding at low temperature. Cold adaptations apparently superimpose on pre-existing cellular organization, resulting in different adaptive strategies. In addition, microbial lifestyle further modulates the properties of the chaperone machinery, which possibly explains the occurrence of cold-adapted and non-cold-adapted protein chaperones in psychrophiles.
authors.affiliation: Laboratory of Biochemistry, Center for Protein Engineering, University of Liège, Institute of Chemistry B6a, 4000 Liège-Sart Tilman, Belgium.
authors.forename: Florence
authors.initials: F
authors.lastname: Piette
authors.forename: Caroline
authors.initials: C
authors.lastname: Struvay
authors.forename: Georges
authors.initials: G
authors.lastname: Feller
mesh_terms: D000222:Adaptation, Physiological; D001105:Archaea / Q000378:metabolism / Q000502:physiology*; D018407:Bacterial Physiological Phenomena; D003080:Cold Temperature; D019848:Gene Expression Regulation, Archaeal; D015964:Gene Expression Regulation, Bacterial; D018832:Molecular Chaperones / Q000378:metabolism; D014176:Protein Biosynthesis; D017510:Protein Folding
chemical_list: D018832:Molecular Chaperones